wait-for is designed to synchronize services like docker containers. It was inspired by eficode/wait-for, but completely rewritten in golang. It is extremely lightweight (based on the docker scratch image).
% ./wait-for
Usage: ./wait-for [OPTIONS] host:port
-interval int
minimum interval (in second) between connection attempts (default 1)
-timeout int
timeout (in second) before the program exits with an error code